结肠腺瘤性息肉病蛋白在二甲肼诱导大鼠大肠癌中的表达和意义  

Expression and Significance of Tumor Suppressor Gene APC Protein in the Rat Colorectal Carcinoma Induced by Dimethylhy Drazine

作　　者：马晓强[1] 王伟杰[1] 李海[1] 

机构地区：[1]宁夏医科大学总医院结直肠外科,银川750004

出　　处：《宁夏医科大学学报》2014年第8期842-845,F0004,共5页Journal of Ningxia Medical University

基　　金：宁夏自然科学基金(NZ10155)

摘　　要：目的结肠腺瘤性息肉病蛋白(adenomatous polyposis col,APC)在二甲肼诱导大鼠大肠癌中的表达及意义。方法 60只雄性SD大鼠,随机分为对照组(皮下注射生理盐水,20只)和模型组(皮下注射二甲肼,40只),两组均在注射25周后停药,继续喂养5周,于饲养后第10、16、20、25周末,分别处死2只大鼠,其余大鼠于饲养后第30周末处死。HE染色基础上,光镜下观察病理变化;应用蛋白印迹法(western blot)、免疫组织化学法(IHC),检查大肠癌、大肠腺瘤、正常大肠粘膜组织中APC蛋白表达情况。结果于第16、20、30周,与对照组相比,模型组大鼠体重明显降低[(326.4±18.3)g与(322.1±12.8)g;(330.7±12.1)g与(315.0±12.2)g;(341.7±10.2)g与(310.0±8.4)g)(P均<0.05);模型组大鼠共获取大肠腺瘤组织27个,大肠癌组织39个;对照组除2只大鼠大肠粘膜局部增厚外,未见肿瘤病灶;大肠腺瘤、大肠癌组织与对照组中的APC相比,其阳性表达率明显降低(35%与90%;10%与90%)(P均<0.05);通过western blot检测发现,APC蛋白在正常大肠粘膜组织中表现为分子量约300KD的特异性蛋白条带,而在大肠癌、大肠腺瘤组织中没有该特异性条带的表达。结论 APC在正常大肠粘膜组织中强表达,而在大肠腺瘤、大肠癌组织中低表达或不表达,表明APC与大肠癌的发生、发展存在密切相关性,可能是大肠癌的重要肿瘤标志物。Objective To investigate the expressio protein in the rat colorectal carcinoma induced by were randomized into the control group （hypodermic n and significance of adenomatous polyposis col （APC） dimethylhydrazine （DMH）. Methods 60 male SD rats injection of sline,20 rats） and the model group （hypoder- mic injection of DMH,40 rats）. The injections in the two groups were discontinued in 25 weeks and then the rats were fed for 5 weeks. 2 rats in the two groups were respectively killed on the weekend of the 10th, 16th, 20th,25th week after feeding, and the other rats were sacrificed on the weekend of the 30th weeks after feed- ing. The pathological changes were observed by the light microscope on the basis of HE staining and the APC protein expression in the colorectal carcinoma, colorectal adenoma and normal colorectal mucosa tissues were detected by western blot and immunohistochemistry （SP） methods. Results Compared with the control group ,the body weights were significantly decreased in the model group on 16th ,20th and 30th week（326.4 ± 18.3 vs 322.1 ±12.8;330.7 ±12.1 vs 315.0 ±12.2;341.7±10.2 vs 310.0 ±8.4,P 〈0.05）. 27 colorec-tal adenoma tissues and 39 colorectal cancer tissues were obtained inthe model group rats while no tumor foci was found in the control group except 2 only outside the local thickening of colon mucosa in rats . Compared with the normal colorectal mucosa, the positive expression rate of APC protein in the colorectal adnoma and colorectal carcinoma tissues were significantly reduced（35% vs 90% ,P 〈 0.05;10% vs 90% ,P 〈 0.05）. Western blot examination showed that APC protein expression was the specific protein band with the molecular weight of about 300KD in the normal colorectal mucosa,while no expression of the specific bands in the color- ectal carcinoma and colorectal adenoma tissues. Conclusion The APC protein expression is strong positive in the normal colorectal mucosa and low or no expression in the colorectal adenoma and colorectal carcinoma tis

关 键 词：结肠腺瘤性息肉病蛋白 大鼠 大肠癌 

分 类 号：R735.34[医药卫生—肿瘤]